Pigeonpea intercropping in maize based cropping systems

In Probolinggo area the predominant maize based "tegal" (dry land) cropping system is a rainy season maize monocrop followed by a maize/lab-lab bean intercrop. The maize in the maize/lab-lab intercrop is harvested shortly after the end of the reliable rainy season. The lab-lab bean grows through into the dry season, utilising residual soil moisture and the variable late rains. Pigeonpea could be used in a similar way to lab-lab bean to utilize dry season soil moisture. A randomized block field experiment in five blocks was conducted at Muneng Research Station near Probolinggo, during November, 1988 until September 1989. The blocks were regularly sprayed with insecticides and the other two blocks were not sprayed. There were six treatments namely (1) Maize followed by maize/lab-lab; (2) Two rows of maize and one row of local pigeonpea followed by maize/lab-lab; (3) Four rows of maize and one row of local pigeonpea followed by maize/lab-lab; (4) Six rows of maize and one row of local pigeonpea followed by maize/lab-lab; (5) Two rows of maize and one row introduced pigeonpea followed by maize/lab-lab; (6) Four rows of maize and one row of pigeonpea followed by maize/lab-lab. There was no significant spraying on maize yield, however there were large and significant effects on pigeonpea yields. Mean pigeonpea grain yield with spraying was 1,0 t/ha for the local variety and 0,4 t/ha for Mega. Yield without spraying were 0.04 t/ha and 0,01 t/ha, for local and Mega respectively. In rainy season the mean sole crop maize grain yield of 2,2 t/ha was not significantly affected by intercropping. In the second maize crop (dry season), sole maize grain yield was 3,3 t/ha and slightly higher but were significantly reduced by intercropping especially at narrower row arrangement and for the local pigeonpea variety. Lab-lab seed yield in sole maize treatment was 0,9 t/ha followed by intercrop with Mega (0,8 t/ha) and intercrop with local pigeonpea (0,2 t/ha). Economically if the price of pigeonpea is still lower than lab-lab, there is no net economic benefit to intercropping with pigeonpea.