Hot pepper grown in greenhouse

Greenhouse pepper production was one of the fastest growing in the last decade. Well-accepted by consumers, greenhouse peppers now offer a new income option for small and medium-sized producers, as well as an investment opportunity for retired professionals. 

Regardless of its origin, the producer always questions technicians about the best way to grow peppers in the greenhouse. There are several questions: What is the recommended spacing? What tutoring system should be used? Should plants be trained with 2, 3 or 4 stems? 

Faced with so many doubts, the Faculty of Agricultural Sciences at UNESP in Botucatu/SP (FCA) researched the cultivation of red peppers in a greenhouse for two years. Two production seasons, six commercial hybrids, three spacings, two staking systems and 4 training systems were tested. Based on these results, some recommendations could be extracted. 

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Tutoring systems

One of the first decisions to be made by the producer is regarding the staking system to be used. The FCA compared the “V” staking systems and the simple espalier system. 

“V” cultivation consists of a pair of posts planted at the ends of each windrow and another pair in the center of the windrow, in such a way as to form a “V”. These fence posts must be secured with battens approximately 2,5 meters above the windrow, and approximately 1 meter apart. It is recommended to place a stop on the posts 25 cm above the windrow, with the purpose of serving as a support for a number 18 wire, which will pass through the center of the windrow, and support the plants at the height of the first fork. This additional care prevents the plants from falling under the weight of the first fruits. 

Two other strands of the same type of wire must be placed 2,5 m above the windrow, connecting the posts, with the purpose of supporting and aligning the bamboo poles used in the “V” cultivation staking system. It is also recommended to place two 3 meter long bamboo poles every 2,5 meters for better support. In their upper part, these bamboo sticks must be tied to one of the two wire strands.

As the plants grow, plastic ribbons for tying bags or wire strands must be placed to serve as support for the plants, whose stems must be periodically tied. The ribbons or wire strands are supported by the bamboo poles. One thing to be careful about is to only attach the stems that are supported by one of the ribbons or wire strands because when the stem of a plant is hung on the support, it can break under the weight of the fruits. The distance between the ribbons or wire strands, which are arranged horizontally, must be 15 to 20 cm apart.

The simple espalier staking system consists of a fence post placed at the ends of each row and another in the middle of the row, so that they are aligned with the row of plants. Approximately 25 cm above the windrow, a number 18 wire must be placed to support the plants at the height of the first fork, as they may fall under the weight of the first fruits. This wire is attached to the posts and is also supported by bamboo poles, placed no more than 2,5 m apart. In simple espalier staking only one bamboo pole is used while in the “V” staking system two poles are required. In both cases, the bamboo poles must be attached to the upper wire.

In the simple espalier staking system, plastic ribbons for tying bags or wire strands must be placed to serve as support for the plants. The big difference in this staking in relation to “V” cultivation is the spacing between the ribbons or wire strands, which can be up to 30 cm. 

A basic cost calculation is capable of demonstrating that staking the pepper crop using the simple espalier system ends up being cheaper for the producer than “V” cultivation. Furthermore, day-to-day cultivation is much easier when pepper cultivation is managed using the simple espalier system. 

On the other hand, staking the pepper crop through “V” crop staking showed greater productivity per meter for the red pepper hybrids evaluated. For example, the Margarita hybrid achieved a productivity of 7,1 kg in “V” cultivation and only 6,5 kg with simple espalier staking. This represents that the “V” cultivation produced 9,2% more than the simple espalier. But does the greater productivity of “V” cultivation versus the price that the market pays for your greenhouse peppers compensate for the greater expense in staking and managing the crop? Answering this question is key to deciding which tutoring system to choose.

There are many details that made one staking system better than the other, that is, adapting the recommendations mentioned here is essential for the success of your crop. Therefore, consult the Agricultural Engineer in your region and discuss with him the best alternative for your case.

Spacing between plants

Choosing spacing seems to be easier. The work carried out by FCA-UNESP evaluated six different hybrids in two planting times and spacings of 25 and 33 cm between plants were more productive than spacing of 50 cm. The productivity of red pepper hybrids when transplanted between 25 and 33 cm was similar. Therefore, the best options for the producer are spacings of 25 and 33 cm. In general, the average fruit weight was not changed by any of the treatments.

Driving systems

The management of the red pepper plant is the detail that makes the biggest difference. For example, the Athens and Elisa hybrids evaluated in the FCA experiment showed better productivity with four stems per plant or free-growing plants (without pruning). The results of the experiments suggest that the Commandant hybrid should preferably be grown with four stems per plant, while the Margarita, Safari and Vidi hybrids can be grown with three or four stems per plant.

Considering the volume of service that pruning red pepper crops in a greenhouse represents, and therefore the cost of labor, the decision on how to manage the plants will have a major impact on the final production cost. It is also worth noting that the experiment carried out by FCA in Botucatu evaluated only 6 hybrids, and the producer has dozens of pepper hybrids available on the market. Once again, don't forget to consult an Agricultural Engineer and get more information about which hybrid to choose when planting.

Sebastião W. Tivelli and R. Goto

This article was published in issue number 07 of Cultivar Hortaliças e Frutas magazine, April/May 2001.