In this work, we studied the effect of different substrate mixes composed of blond peat and compost produced from solid urban waste, vegetable waste, and vine pomace on the quality of tomato seedlings (Solanum lycopersicum cv. Dakapo). Each compost was mixed with blond peat at different ratios such that the initial electric conductivity (EC) of the final mixes was 2.5, 3.5, and 4.5 dS·m−1. The following control substrates were used: blond peat and blond peat + black peat + standard coconut fiber used in commercial nurseries on experimental basis. Emergence and several seedling quality variables were monitored. Results showed that peat in nursery substrates can be partially substituted by these composts to grow tomato seedlings. The quantity of vegetable waste and vine pomace compost used should not allow the initial EC to exceed 2.5 dS·m−1.
Manuel Díaz-Pérez and Francisco Camacho-Ferre
María Victoria Huitrón-Ramírez, Marcia Ricárdez-Salinas and Francisco Camacho-Ferre
One of the major problems of watermelon production is the decrease of fruit yield and quality caused by soil diseases. Soil disinfection with methyl bromide (MB) has been used to prevent fungus attacks; however, its use is being restricted because this substance damages the ozone layer. Searching for new MB alternatives, field experiments were carried out in open field in soils infested with Olpidium bornovanus and melon necrotic spot virus in Colima, Mexico, where watermelons had only been grown previously using soil fumigation with MB. Yield and quality of watermelon cultivar triploid Tri-X 313 grafted on two rootstocks of Cucurbita maxima × Cucurbita moschata (‘RS841’ and ‘Shintosa Camelforce’) were evaluated during 2 consecutive years. Each experiment had five treatments, two of them with nongrafted plants at a density of 3472 plants/ha with and without MB fumigation. The remaining three treatments had grafted plants in nonfumigated soil with plant densities of 2778, 2083, and 1740 plants/ha. The use of watermelon grafted on ‘RS841’ and ‘Shintosa Camelforce’ rootstocks significantly increased the average fruit weight and the total yield of watermelon in soil without the need for MB. Grafting may be considered as an alternative MB fumigation. With the use of grafted watermelon plants, planting density may be reduced by 50%, obtaining higher yields than those obtained from nongrafted plants grown on fumigated soil except for ‘Tri-X 313’ grafted on ‘Shintosa Camelforce’ in 2006–2007. Fruits harvested from grafted plants had higher firmness than those harvested from nongrafted plants without affecting the content of soluble solids.
Francisco Doñas-Uclés, Diego Pérez-Madrid, Celia Amate-Llobregat, Enrique M. Rodríguez-García and Francisco Camacho-Ferre
In the southeast of Spain, specifically in the province of Almería, pepper production represents 1.70% of the total pepper (Capsicum annuum L.) production in the world, which in turn represents 31.8% of the European production. In the last 10 years, production has remained stable between 7,240 and 10,997 ha. Due to the economic importance of this crop in the region, more improvements of the production techniques have been adopted. The reduced number of commercial rootstocks of peppers, which really improve yield in this crop, causes a continuous search for new genotypes. In this experiment, five pepper rootstocks were evaluated in an experimental design of randomized blocks with six treatments and three repetitions. The rootstocks used were: ‘Serrano de Morelos 2’ (SCM-334), ‘Jalapeño’, ‘Oscos’, ‘AR 9604040’, and ‘Tresor’. The cultivar grafted onto them was ‘Palermo’ also used as a control test. SCM-334 cultivar used as rootstock has a similar behavior in the production parameters measured as the commercial pepper rootstocks which were used. ‘Jalapeño’ and ‘SCM-334’ demonstrated different behavior in plant vigour compared with the others treatments. There is no interrelationship between production and plant vigour provided by the rootstock.
Francisco Javier Núñez, Maria Victoria Huitrón, Manuel Díaz, Fernando Diánez and Francisco Camacho-Ferre
In Spain, the adoption of the triploide ‘Queen of Hearts’ (Citrullus lanatus Thunb.) watermelon cultivar has brought important changes in the production of seedless watermelon thanks to its magnificent acceptance by the market. The experiments on triploid watermelon presented here examined innovative production techniques that would guarantee the productivity and quality of this cultivar in plastic greenhouses and improve cost-effectiveness, serving growers. Crop intensification was tested under a “temporary trellis” management system, increasing plant density from 2500 plants/ha in the traditional or creeping crop system to 10,000 plants/ha. The “temporary trellis” system was combined with fruit set through the localized application of a 150- to 200-mg·L−1 solution of 1-(2-chloro-4-pyridyl)-3-phenylurea (CPPU). The increase of grafted watermelon plant density to 1 plant/m2 gave rise to an increase in early harvest measured as the number of fruits per surface area compared with the traditional system with a density of 0.25 plant/m2. In addition, a process of temporary trellising facilitates choosing female flowers for applying CPPU. The °Brix and pulp firmness quality parameters did not show significant differences between “temporary trellised” and creeping crops.