Evaluating the forage potential of maize (Zea mays L.) cowpea (Vigna unguiculata L.) intercropping under various planting ratios and harvesting time

To investigate the forage potential of maize (Zea mays L.) - cowpea (Vigna unguiculata L.) intercropping under various planting ratios and harvesting time, a field experiment was conducted during kharif season year 2013 at Agronomic Research Area, University of Agriculture, Faisalabad. Randomized Complete Block Design (RCBD) with factorial arrangement was used with three replications using the net plot size of 3.0 m x 6.0 m. The experiment comprised two factors. Factor A (Planting Ratios) contained five treatments; I (sole maize), ii (sole cowpea), iii (intercrop of maize 50% + cowpea 50%), iv (intercrop of maize 70% + cowpea 30%) v (intercrop of maize 30% + cowpea 70%) and Factor B (harvesting time) comprised two treatments i(harvest at milky stage), ii(harvest at dough stage). Forage maize variety Sargodha 2002 and forage cowpea variety Rawan 2003 was sown using seed rate of 100 kg per ha and 30 kg ha, respectively by keeping row to row distance 30 cm. All other agronomic practices and inputs were kept normal and uniform for all treatments. The data were recorded using standard procedures for various agronomic traits. The observations were investigated by using Fisher's analysis of variance method and variation within means of treatments was comparatively analyzed using least difference test (LSD) at 5% probability. The results showed that seed planting ratios and harvesting times significantly influenced all parameters such as plant population, plant height and leaf area per plant of maize, mixed fresh forage yield, crude protein contents, crude fiber contents and ash percentage. Maximum per hectare yield (46.38 t per ha) was recorded by maize sole crop and the treatment of sole cowpea showed higher values of crude protein (17.31 %) and total ash (9.68%), while lowest value of crude fiber (28.22%). All intercrops resulted in better forage quality as compare to sole maize crop. Among intercrops intercrop maize 70% and cowpea 30% resulted in higher per hectare forage yield (43.33 t per ha) with improved quality. Harvesting the maize forage at dough stage increased per hectare yield but decreased the quality of the forage. It is concluded that the intercropping of maize with cowpea is better choice for quality forage. In order to obtain good forage yield with better quality, maize should be grown in association with cowpea and harvesting should be done at milking stage.