Production efficiency of ‘BRS Pujante’ cowpea using single and dual Kc for irrigation¹

Eficiência produtiva do feijão-caupi “BRS Pujante” usando irrigação com Kc único e dual

HIGHLIGHTS:

The highest water consumption at cowpea occur in 3^rd stage.

Chlorophyll indices are not altered by the use of different types of Kc.

The use of dual Kc can optimize the water use in cowpea.

ABSTRACT

The objective of this study was to evaluate the production efficiency of cowpea (Vigna unguiculata L. Walp.), ‘BRS Pujante’, from the weather-based irrigation scheduling using single and dual Kc. The study was carried out in randomized block design with two treatments (single and dual crop coefficient) and 12 replicates. Chlorophyll a, chlorophyll b and total chlorophyll contents, soil matric tension, number of pods per plant, number of grains per pod, average 100 grains weight, total grain yield and water use efficiency were evaluated. Scheduling with single and dual Kc did not interfere with chlorophyll pigments. Single Kc promoted tension values closer to zero during cowpea development stages III and IV. Significant difference was observed only for the average 100 grains weight, with higher value for dual Kc. The irrigation depth with the single Kc was 360.8 mm and there was a 9.3% water saving when compared to dual Kc, without significantly affecting cowpea yield. It is possible to use irrigation scheduling with single Kc for the stages I and II and dual Kc for the stages III and IV of cowpea, ‘BRS Pujante’.

Key words:
Vigna unguiculata L. Walp; irrigation water use efficiency; weather-based scheduling