Allelopathic effect of Libidibia ferrea Mart. on the vigor of cowpea seeds

Abstract

The cowpea is one of the main crops of importance for the Northeast region, being cultivated in areas of the Caatinga, considering that it is necessary to study the interaction between agricultural crops and forest species in this biome. Therefore, the present study aimed to evaluate a possible allelopathic influence of dried leaves in the decomposition process of Libidibia ferrea Mart. on the development of caupi bean seedlings, cv. Canapu. The leaves of the forest species were collected in the morning and dried at 40 ºC for 24 hours in the greenhouse, then were manually fragmented and added to sand forming the substrate, the following proportions of dry leaves and sand were adopted: 1:0 (control); 1:1/2; 1:1 and 1:2 (v:v). The substrates were decomposed for 15, 30, 45 and 60 days, the control treatment without decomposition, so subsequently the seeds of cowpea were sown. The seedling height and root length, dry mass of the aerial part of the root system and total normal seedlings were evaluated. The entirely randomized 4x5 factor scheme was used (sand proportions: dry leaves x periods of decomposition). The period of 30 days of decomposition causes a reduction in the length of the aerial part, in the dry mass of the aerial part, in the root system and in the total of the seedlings, the increase in the proportions of dry ironwood leaves affects the dry mass of the aerial part and total of the seedlings. Therefore, the cultivation of caupi beans, cv. Canapu, and ironwood in an agroforestry system is not feasible.