The use of colored shade nets is a method to protect plants from direct solar radiation and optimize the light spectra they transmit. The purpose of this work was to evaluate the photosynthetically active radiation (PAR), the photosynthetically active integrated radiation (IPAR), temperature, relative humidity, growth, production, and fruit quality of Physalis ixocarpa variety Tecozautla, cultivated under nets generating 60% shade in the colors beige, blue, green, red, and black and under a treatment without netting (control group). Different variables were observed: climatic variables, such as radiation, temperature, and relative humidity; growth variables, such as plant height and stem diameter; production variables, such as number, weight, and caliber of the fruit; and quality variables of the fruit, such as pH and total soluble solids. The highest PAR, IPAR, and temperature and lowest relative humidity were obtained in the absence of netting. The white net resulted in the highest PAR and IPAR but no difference in temperature or relative humidity. In addition, an increase in the height, stem diameter, number of branches, and weight, number, and size of the fruit was observed. The white net resulted in the highest yield: 88% higher than in the control group. The pH of the fruit was significantly higher under the white netting, and no differences among the treatments in terms of the content of total soluble solids were found.
Isidro Morales, Gabino Alberto Martínez-Gutiérrez, Cirenio Escamirosa-Tinoco, Cinthia Nájera, Tatiana Pagan Loeiro da Cunha-Chiamolera and Miguel Urrestarazu
Lucia Armin Langlé-Argüello, Gabino Alberto Martínez-Gutiérrez, Patricia Araceli Santiago-García, Cirenio Escamirosa-Tinoco, Isidro Morales and José Raymundo Enríquez-del-Valle
The Agave potatorum Zucc. is a wild species endemic to Oaxaca and Puebla, Mexico. The stem or “head” of the plants of this species contains a large amount of fructans, which, in conjunction with their crassulacean acid metabolism (CAM), helps the agave to survive droughts. The soluble carbohydrates are used to produce mezcal. The objective was to evaluate growth and content of fructans of A. potatorum young plants grown in soil and perlite substrate, fertigated with three nutrient solutions, and subjected to drought. Eight-month-old plants were used and, for 15 months, were fertigated with nutrient solutions: 1) Steiner, 2) Hoagland and Arnon, and 3) Urrestarazu. Irrigation was later suspended to simulate a 5-month drought and induce stress. During fertigation, the vegetative growth was greater in plants irrigated with Hoagland and Arnon and Urrestarazu solutions in perlite and in soil. After the period of water deficit stress, plants in perlite substrate fertigated with the Hoagland and Arnon solution accumulated more fructans in the heads, reaching a maximum of 75%, than plants in soil substrate (42%).