Phosphorus doses alter the ionic homeostasis of cowpea irrigated with saline water

HIGHLIGHTS Irrigation using water with electrical conductivity above 2.5 dS m-1 is not adequate for ‘Paulistinha’ cowpea. Increment in phosphorus dose does not increase phosphorus content in cowpea plant. Under salt stress conditions, cowpea plants require lower doses of phosphorus.

Cowpea Yield Performance in an Alley Cropping Practice on an Acid Infertile Soil at Ebini, Guyana

The yield performance of cowpea var. Minica # 4 (Vigna unguiculata L.) on an Arenic Paleudult (Acrisol) was evaluated in an alley cropping experiment with Gliricidia sepium (Jacq.) Kunth ex Walp., Leucaena leucocephala (Lam.) de Wit and a treeless control during a short- (November-December 2004), and long-(May-June 2005) rainy season at Ebini, Guyana. The alley cropping treatments had no significant effect on cowpea plant height, pods per plant, pod weight per plant and grain weight. During the short-rainy season, values for cowpea plant height and number of pods per plant were higher compared to those for the long-rainy season, and number of pods per plant was positively correlated with pod weight. During the long-rainy season, pod weight and grain weight were correspondingly higher. Plant height vs. number of pods per plant; number of pods per plant vs. pod weight; and, number of pods per plant vs. grain weight, were all positively correlated. Cowpea could yield the same or more when associated with managed fast growing, nitrogen (N)-fixing trees or treeless plots. This alley cropping practice has the potential to reduce the use of fossil-fuel generated fertilizers and reduce the potential production of an important greenhouse gas (GHG).