Development and production of bean cultivars (Phaseolus vulgaris) in winter cultivation under different spacing

Beans (Phaseolus vulgaris L.) occupy a prominent place in Brazilian agriculture, being characterized as a strong product on the domestic market, whose grains represent an important source of protein and minerals in the population's diet, in addition to having notable socioeconomic importance. The common bean is the most cultivated species of the genus Phaseolus in the world (YOKOYAMA, 2002).

Beans are one of the basic foods of many people, especially Brazilians, constituting their main source of vegetable protein. Its protein content can reach 33% with an energy value of 341 cal/100g (Pompeu, 1987). In the last five years, bean production in Brazil ranged from 2,3 to 3,2 million tons in an area that has remained between 4500 and 5800 thousand hectares (BANNO, 1994).

The Americas account for 43,2% of global consumption, followed by Asia (34,5%), Africa (18,5%), Europe (3,7%) and Oceania (0,1%). Developing countries are responsible for 86,7% of world consumption. In Brazil, per capita consumption of beans in the 70s was 18,5 kg-1 inhabitant-1 year-1; In 2002 it dropped to 16,3 kg-1 inhabitant-1 year-1 (EMBRAPA, 2005).

The population and spacing between plants affect the amount of water, light and nutrients used by the crop. Morphological changes such as plant height, leaf area and branches formed determine the plasticity of the cultivar used (BRADSHAW, 1965).

As for sowing, the recommended times are basically concentrated in three periods, the so-called "water" period, in the months of September to November, the "dry" period or off-season, from January to March, and the autumn-winter period. or third season, from May to July. In autumn-winter or third season planting, which can only be carried out in regions where the winter is mild, without the occurrence of frost, such as in some areas of São Paulo, Minas Gerais, Goiás and Espírito Santo, the farmer, as a rule, , you need to irrigate the crop. During the "dry" season, rainfall is not always sufficient throughout the crop cycle, and in this case it is advisable to supplement it with irrigation (EMBRAPA, 2003).

Winter beans are among the most planted crops in production systems operated under sprinkler irrigation in the Cerrado area, due to their attractive profitability and rapid economic return. Applications of adequate dosages of irrigation and fertilization at opportune times, together with a balanced plant population, contribute to higher levels of bean productivity, above 3.000 kg/ha, compatible with irrigated agriculture on a rational basis (AZEVEDO, 2008).

In Brazil there are a large number of genotypes with distinct characteristics from the most varied commercial groups (black, carioca, purple and others), however, beans from the Mesoamerican group are preferred by the population, and this preference is given by the types of grains carioca and black (CARBONELL et al. 1999).

The climate of the Central West region provides a highly favorable time for seed production, known as “third season” or “winter beans”. From the 80s onwards, with the arrival of irrigation in the Cerrado, the evaluation of the behavior of some crops in the dry season began, including beans (RAVA, 2000).

The experiment was conducted in the field at the UEMS/UUC Experimental Farm, located in the municipality of Cassilândia, Bolsão Sul Matogrossense region, at latitude coordinates 19º06'48" S and longitude 51º44'03"W, at an altitude of 470 meters.

Soil preparation consisted of plowing and two harrowing.

On May 13, 2011, a soil sample was removed using an auger in a conventional way, being a composite and representative sample of the area. After this stage, it was sent to FEPISA (Fundação de Ensino, Pesquisa e Extension de Ilha Solteira). ), where they underwent chemical and physical analysis, in accordance with the specific methodology for soils. (Table 1).

On June 03, 2011, sowing fertilizer was carried out at a dose of 250 kg/ha-1, of the formula 04-14-08 (N-P-K), according to the chemical characteristics of the soil in the experimental area.

A randomized block design was used, with four replications in a 2 x 2 factorial, totaling 4 treatments and 16 plots. The data were transformed by the square root of x + 0,5, according to Banzatto and Kronka (2006) (Figure 1). To compare means and verify the effects of cultivars and spacing, the Tukey test was used, at 5% probability. The Sanest program (Zonta and Machado, 1991) was used to carry out statistical analyses.

Sowing was carried out manually on June 07, 2011, using a spacing of 0,45 and 0,80 m between lines and bean cultivars IAC Alvorada and Colibri, consisting of a total of 16 plots, consisting of six lines with a length of 5m each, after sowing, the area was irrigated manually.

The first evaluation took place on July 07, 2011, when the crop was 30 days after sowing (DAS), analyzing the following parameters:

a) Initial stand: 1 meter was marked from the penultimate line of each plot, counting the number of plants within it.

b) Plant height: 10 plants were collected from the second row of each plot, measuring the height from the neck to the apex of each plant with a ruler graduated in centimeters.

c) Green matter (MV): The same plants used to assess height were taken to the laboratory, weighed, then the average weight was taken divided by the number of plants. Data were expressed in g.planta-1.

d) Dry matter (DM): The same plants used to evaluate green matter were taken into

from the Kraft bag to the oven, at a temperature of 65°C for a period of 24 hours, after the same 24 hours, the material is weighed again on a precision scale of 0,001g.

Data were expressed in g plant-1. On June 27, 2011, the first weeding was carried out, done manually, removing weeds in all blocks, the highest incidence was of burr (Cenchrus Echinatus). As seen in Graph 1, the rainfall was practically 0 ( zero) throughout the crop cycle, and low air humidity made it difficult to retain water in the soil, thus requiring a more frequent irrigation method.

Graph 1. Average temperature, humidity, and rainfall in the experimental area up to 85 DAS. Cassilândia 2011

Drip irrigation was carried out using drip hoses, these being hoses with a diameter of 16mm, a wall thickness of 0,20mm and a distance between emitters equal to 0,20m, with a nominal flow of 1,6l/h, distributing 400 meters of hose throughout the area, with continuous water flow for 10 hours a day, starting in the morning.

On July 25th, nitrogen top dressing was carried out, using EMBRAPA Bulletin 100 as a basis for calculations, applying 52g of urea to plots spaced 0,80 m and 27g to plots spaced 0,45 m.

It was noted the large number of kitties (Cerotoma arcuatus) within each plot, finding a number of three individuals or more per plant, and a large number of perforations in leaves, as a control method neem oil was used as a biological control, the syrup was prepared by diluting 0,250 L of neem oil in 5 L of water, for application a pressure sprayer was used.

The second evaluation was carried out on July 27, 2011, when the crop was 50 DAS, evaluating: stand, plant height, green matter and dry matter, using the same procedure as the first evaluation.

The third evaluation took place on August 22, 2011, when the culture was 75 DAS, not differing from previous evaluations in terms of methodology, and evaluating the same parameters.

On September 26, 2011, the fourth and final evaluation was carried out, initially studying the variables: final stand, plant height, weight of green matter and dry matter, subsequently evaluating other phytotechnical indices such as:

a) Number of pods per plant: 10 plants were harvested from one of the central rows of each plot and the green and dry pods on each plant were counted. Adding green pods and dry pods results in the total number of pods.

b) Number of seeds per pod: the 10 harvested plants were used to determine the number of pods per plant. Thresh the pods from 10 plants from each plot and the seeds will be counted.

c) Height of insertion of the first pod: 10 plants were used from one of the central rows of each plot. The height from the base of the plant to the insertion of the first pod was measured, using a ruler graduated in centimeters.

d) Mass of 100 grains: 100 grains were separated from a portion and weighed on a scale with 0.001g precision.

e) Productivity: all plants from the fifth row of each plot were harvested, the results were converted into kilos of grain per hectare (kg ha-1).

A randomized block design was used, with four replications in a 2 x 2 factorial, totaling 4 treatments and 16 plots. The data were transformed by the square root of x + 0,5, according to Banzatto and Kronka (2006) (Figure 1). To compare means and verify the effects of cultivars and spacing, the Tukey test was used, at 5% probability. The Sanest program (Zonta and Machado, 1991) was used to carry out statistical analyses.

Plant emergence occurred at 6 DAS (days after sowing), due to failure in germination, plant thinning did not occur.

Table 2 shows the results for plant stands in relation to the cultivars Colibri and Alvorada and the spacings of 45 and 80 cm. According to the results, there was a reduction in the number of plants per area from the beginning of the cycle to the time of harvest. There was a significant difference only for the first two evaluations, the number of plants was greater with an increase of 51% at 30 DAS and 60% at 50 DAS for the Colibri cultivar, regarding spacing, no significant difference was observed.

During the crop cycle there were minimum temperatures of 11°C as can be seen in Graph 1. The occurrence of low temperatures during the initial development of the crop contributed to the reduction in plant stand.

Table 3 shows the average values ​​for green matter production in g.plant-1 in relation to the Colibri and Alvorada cultivars and at spacings of 0,45 and 0,80 m. According to the results, there was a difference between the cultivars in the initial evaluations (30 and 50 DAS), and from the evaluation at 50 days after sowing (DAS) the Alvorada cultivar provided greater production of green matter. The 0,80 m spacing provided a greater number of green matter from 65 DAS compared to the lower spacing.

The average values ​​for dry matter production in g.plant-1 are presented in Table 4. It is observed that in relation to the cultivars, the results did not differ statistically for dry matter production from 50 DAS onwards. Regarding spacing, the 0,80 m spacing provided an increase from 65 DAS onwards. Cruciani et al. (1998) evaluated the effect of nitrogen fertilization applied through irrigation water on Carioca cultivar beans, in evaluations at 30, 42, 50 and 60 days after germination, they obtained results for conventional fertilization of 863,2 to 4.005,0 kg. ha-1 in the initial and final assessment respectively observing evolution in dry matter accumulation according to the crop cycle. In this study we observed a reduction in the accumulation of dry matter due to the maturation of the bean harvest.

Table 5 shows the results for plant height. The Alvorada cultivar showed greater height at harvest and the 0,80m spacing also provided plants with greater height from 65 DAS onwards, a result that is consistent with what was observed for the production of green and dry matter. At 50 DAS it became possible to identify the growth habit between the cultivars, designating a determinate growth habit for the Colibri cultivar and an indeterminate growth habit for the Alvorada cultivar.

The results obtained related to yield are presented in Table 6. It is observed that the Colibri cultivar provided an increase in all yield parameters studied in relation to the Alvorada cultivar, with the Colibri cultivar providing a number of pods per plant of 11,35 , a number of grains per pod of 3,7, weight of 100 grains of 33,59 and productivity of 1.601,08 kg ha-1, values ​​much higher than those obtained for the Alvorada cultivar which at the time of harvest had greater height, greater accumulation of dry matter and uneven ripening.

Didonet and Costa (2004) studied the parameters involved in the yield of bean plants in winter cultivation, with the cultivar Jalo Precoce and the experimental lineage with a determined growth habit PR93201472 in spacings of 30, 40 and 50 cm and obtained an average yield of 2.458 and 2.797 kg ha-1 for the cultivars respectively and in relation to spacing, the highest values ​​were observed for the 40 cm spacing. In this study, the results for productivity were lower, and this fact can be attributed to the low temperatures that occurred at the beginning of the crop cycle (Figure 1). The same authors obtained greater grain mass in the upper spacing, corroborating this study and observed a positive correlation between the parameters number of pods per plant and number of grains per pod and grain yield, a fact also evidenced in this study.

Due to the infestation of cows (Cerotoma arcuatus) there was a loss of grains and pods, according to Teixeira (1993), in bean it has been observed that in addition to leaf and grain attack, Cerotoma arcuatus larvae feed on nodules and roots, thus decreasing the nodular mass and, as a consequence, impairing biological nitrogen fixation.

The insertion height of the first pod is an interesting parameter when considering the possibility of mechanized harvesting. According to Souza et al. (2009) the architecture of the bean plant constitutes a problem when considering the low insertion height of the first pod, as this characteristic makes harvesting with a self-propelled machine unfeasible. Moura et. al. (1977) and Medina (1992) did not find an effect of variation in the plant population on the height of pod insertion. In this study, no statistical differences were observed according to the factors analyzed, with the insertion height of the first pod being 0,11 m for the Colibri cultivar and 0,14 m for the Alvorada cultivar (Table 7).

For winter cultivation, among the cultivars analyzed, the one that presented a superior development was Colibri, providing greater productivity and a more uniform stand, in contrast, the IAC Alvorada variety presented a more uneven stand, and lower productivity, due to climatic conditions. , due to water deficit, the Colibri cultivar also proved to be more resistant.

Regarding spacing, the 0,80 m spacing proved to be more effective when compared to 0,45 m, allowing significant differences for all productivity variables analyzed.

Cristhy Willy da Silva Romero, Danila Comelis Bertolin, Rafael Leonardo de Souza Pereira

UNESP - Ilha Solteira