EFFECT OF DRIP IRRIGATION APPLICATION REGIMES AND MULCHING ON SOIL PROPERTIES, GROWTH AND YIELD TRAITS OF TOMATO (SOLANUM LYCOPERSICUM L.) VARIETIES

Abstract

Agriculture in northern Ghana is challenged by drought and erratic rainfall pattern which greatly affects productivity of Tomato. The poor crop yield results in demand shortfall and subsequently importation of tomatoes from neighbouring countries. This research was conducted at the CSIR-SARI, Nyankpala to investigate the effect of drip irrigation application regimes and mulching on soil properties, physiological and yield traits of tomatoes. The experimental design was a split-split plot. Treatments consisted of tomato variety as mainplot factor at two levels (Mongal F1, Pectomech), irrigation regimes as subplot factor at three levels (100 % crop water requirement (ETc), 75 % ETc and 50 % ETc), and quantity of rice straw mulch as sub-subplot factor at three levels (6 t ha-1 , 3 t ha-1 and 0 t ha-1 ). Results showed that soil water content, soil pH and soil temperature were significantly improved by the full irrigation regime and 6 t ha-1 mulch. The total fruit yield (TFY) was significantly affected by treatments. Mongal F1 produced more TFY that ranged from 9.4 - 12.08 t ha-1 . Also, 100 % ETc produced the highest TFY ranging from 7.24 - 9.56 t ha-1 . The 6 t ha-1 mulch gave more TFY between 8.54 - 9.42 t ha-1 compared to no-mulch treatment. Furthermore, the irrigation water-use efficiency was highest for Mongal F1 and ranged between 2.43 - 3.07 kg m-3 . Interaction of Mongal F1 and 50 % ETc produced 3.88 kg m-3 . The crop water stress index showed plant stress condition for 50 % ETc, followed by 75 % ETc as well as no-mulch. Also, brix and pH content of fruits were influenced by treatments. Pectomech had more brix content than Mongal F1. Deficit irrigations (50 % and 75 % ETc)improved brix content compared to full irrigation. Pectomech in combination with 3 t ha-1 mulch as well as Pectomech in combination with 50 % ETc gave highest brix content of 8.16 % and 8.67 % respectively. The CROPGRO -Tomato Model was excellent in simulating soil temperature, canopy height and fresh fruit yield of tomatoes. The adoption of Mongal F1 in combination with deficit irrigation regimes and rice straw mulch would improve water and crop productivity of tomato under water scarce environments.