A comparison of legume intercycle crops for pineapples

These experiments were conducted at the Wahiawa Sub-station, Island of Oahu, T.H., with the purpose of testing the value of six leguminous plants, namely, Cajanus cajan, Crotalaria juncea, C. spectabilis, C. anagyroides, Stizolobium utile, and Cassia tora under ordinary growth conditions. 1. The Latin square method of plat arrangement was followed. The soil of the plats was acid, pH value 4.9, and very low in available phosphorus. Both of these conditions were unfavorable to the good growth of the tested crops. 2. Relative germination of the respective lots of seed, tonnage of the crops on a wet and dry basis, and amount of nitrogen fixed were considered as indices of the suitability of the crops. The data were mathematically interpreted. 3. Cassia tora did not prove acceptable as a cover crop under any conditions provided in this test. 4. The plants tested may be divided into two general groups with respect to growth period. Crotalaria juncea and Stizolobium utile excelled in wet weight and nitrogen content at the end of the 91-day period. Crotalaria juncea had produced at this period 7,006 pounds of wet material of which 68.83 +/- 0.96% was moisture and 2.34 +/- 0.025% nitrogen, while Stizolobium utile produced 8,511 pounds of wet material containing 77.58 +/- 0.25% moisture and 2.21 +/- 0.156% nitrogen. The remaining plants, together with S. utile, proved most acceptable after 197 days of growth. 5. In brief, the legumes may be arranged in descending order with respect to the following: A. Wet weight at the end of the 91-day period: Stizolobium utile, Crotalaria juncea, C. anagyroides, C. spectabilis, Cajanus cajan, Cassia tora. B. Wet weight at the end of 157 days: Stizolobium utile, Crotalaria spectabilis, C. anagyroides, Cajanus cajan, Crotalaria juncea, Cassia tora. C. Dry weights at the end of 91 days: Crotalaria juncea, Stizolobium utile, Crotalaria anagyroides, Cajanus cajan, Crotalaria spectabilis, Cassia tora. D. Dry weights at the end of 157 days: Stizolobium utile, Crotalaria anagyroides, Cajanus cajan, Crotalaria spectabilis, C. juncea, Cassia tora. E. Nitrogen content at the end of 91 days: Crotalaria juncea, Stizolobium utile, Crotalaria anagyroides, C. spectabilis, Cajanus cajan, Cassia tora. F. Nitrogen content at the end of 157 days: Stizolobium utile, Crotalaria spectabilis, C. anagyroides, Cajanus cajan, Crotalaria juncea, Cassia tora.