Obtaining New Potato Cultivars with Late Blight Resistance and Adapted to Climate Change Using Participatory Varietal Selection

The potato crop in Peru is the main income and food source for the smallholder of the highland grower of the Peruvian Andes.For urban population,it represents one of the main components of the food basket and for commercial intermediaries.It is the main brokerage product considering its volume and value.To facilitate the adoption and diffusion of new potato cultivars after its release,adequate methodologies are necessary to apply during the process of evaluation and selection.One of these methodologies is called participatory varietal selection(PVS).The objective of this study was to identify new potato cultivars and/or genotypes with resistance or tolerance to adverse effects of climate change applying PVS,in order to obtain new varieties with acceptable economic yields.In this way potato growers of the Peruvian highland Andes should benefit through the improvement of their economic status,food security and overall life quality.During 2016-2017,three potato clones(CIP393079.4,CIP387096.2 and CIP396034.268)and two commercial varieties(Unica,Canchan)were evaluated at eight Peruvian locations in three regions(Huánuco,Junín and Huancavelica).Data were analyzed using a randomized complete block design,with three replications.Main criteria for selection were late blight resistance,abundant foliage,drought tolerance,yield and uniform and healthy tubers.In all three regions the three best clones selected were CIP396034.268,CIP393079.4 and CIP387096.2,ranking in first,second and third place,respectively.Men and women selected the same clones,but in a different order.Commercial cultivars ranked 4th and 5th.However,local growers selected Canchan,CIP387096.2 and CIP393079.4 based on appearance,texture and taste tests.The last two clones(CIP387096.2 and CIP393079.4)should be considered for a future release.

Assessment of Farmer’s Practices on the Rubber Nursery Management Using Growing Medium and Varietal Selection in Mon State

Rubber is an economically important perennial crop in Myanmar for latex production. As the rubber plantation area increases yearly, the requirement of vigorous rubber seedlings for its establishment plays a central role. The success of rubber plantations depends on some farming practices such as using different compost or other materials in the potting soil-medium, varietal selection for stock and scion in the budding process, and fertilizer application methods. The objective of this study was to assess the farmer’s practices in the establishment of rubber nurseries in mostly rubber planted areas in Myanmar. The survey interviewed 60 respondents from three townships in Mon State, namely Mudon, Kyaikmaraw, and Thanbyuzayat. The response data were analyzed through the descriptive method. This survey exposed the potentially active operators (middle age of 30 - 60 years) in rubber nursery production. Local experienced farmers usually raised the budded seedlings with 15 cm × 23 cm polyethylene bag in all study regions. Most farmers selected multi-clonal seed for stock and BPM 24 for scion according to the local market demand and high latex yield. All survey areas used both organic and inorganic fertilizers for nutrient management. Compost is a chief component of growing medium in their nursery production. However, making compost and high demand of the compost were local constraints. Therefore, this survey suggested improving the proper composting method for rubber nursery establishment.

Farmers'participatory selection of new rice varieties to boost production under temperate agro-ecosystems

In mountain agriculture, early maturity, high grain yield and high biomass are generally considered as farmer preferred traits in rice crop in addition to a multiple set of traits collectively responsible for variety adoption or rejection. The varieties tested only on station evaluation trials without taking the data from the farmers＇ fields by not including farmers as partners for variety evaluation are the reasons of low adoption of varieties. In this regard, a participatory methodology was followed by conducting a number of participatory trials in the farmers＇ fields during 2012-2014 in six districts of Kashmir Valley, India. The mother trials in the farmers＇ fields showed that the test variety SKUA-408 consistently and significantly out yielded Jhelum and farmers＇ variety followed by Shalimar rice 3 （SR3）. The other released varieties like SR1 and SR2 could not perform nicely in the farmers＇ fields because of late maturity. After making the t-test comparison of baby trials （paired plots）, the mean yield superiority of test varieties SKUA-408, SR3, and SKUA-403 over farmers＇ variety during 2013 was around 23, 25, and 22％, respectively, whereas in 2014 the respective yield advantage was recorded as 16.3, 17.7, and 16.2％. In all districts, SKUA-408 and SR3 were significantly preferred by farmers （P〈0.05 or 0.01） in terms of pre-harvest traits namely, tillering ability and general phenotypic acceptability, early maturity and biomass and for post-harvest traits such as general cooking quality besides, the intention to grow the variety for next year. Adoption and dissemination of SKUA-408 began in 2014 from the farm-saved seed in the form of farmer to farmer seed exchange. Farmers are the end users of a variety so the decision by the farmers while judging the variety should be taken into consideration to make the varietal choice more effective for its widespread adoption.

Morphological Characterization and Phenological Modeling of <i>Jatropha platyphylla</i>(Euphorbiaceae) Muell. Arg. Genotypes

Morphological characterization and phenological modeling were carried out on genotypes of Jatropha platyphylla collected from the states of Sinaloa and Durango, Mexico. The morphological characterization evidenced the existence of monoecious plants, finding individuals with male and female flowers in the same inflorescence. Fruit with four seeds was also found. The phenological study was divided into two phases and calculated in thermal requirement (°D): Vegetative [seedtime (0), germination (24), emergence (98), cotyledons (87), second (302) and fourth (524) true leaves, end of vegetative growth (302)] and reproductive [flowering (303), fructification (342), maturation (126), defoliation and senescence (450)]. The thermal constant (2558) was similar in all eight genotypes. The phenological stages and the accumulated degree days were adjusted with a third-degree polynomial (Stage = -0.0041x3 + 0.7446x2 - 8.6808x + 6.2448) (R2 = 0.99%) stage. The development of phenological models facilitates the prediction of the flowering date for the selection of varieties with high oil and protein content.

Rooting of Stem Cuttings of <i>Jatropha platyphylla</i>(Euphorbiaceae) in the Obtaining of Axillary Buds for Grafting

Jatropha platyphylla is considered as a potential source of edible protein, oil, and phenolic compounds with anti-inflammatory activity. The use of stem cutting in vegetative propagation and grafting is as indispensable tools for mass multiplication of superior genotypes and helps in improve planting yield and quality. The study was aimed to investigate the effect of different diameters (10 - 15, 16 - 25 and 26 - 35 mm) and different hormone concentrations of indo-butyric acid (0, 1.5, 3, 6 and 10 g/L), in the rooting of Jatropha platyphylla and to obtain axillary buds to performed grafts. Rooting efficiency was 80% in greenhouse conditions. Hormone concentration and diameter significantly affected the rooting and shooting ability of Jatropha platyphylla stem cuttings. Stem cuttings of 26 - 35 mm have the greatest number, length and dry root weight. 76% survival of the grafted plants was obtained. This demonstrates the necessity to improve the conventional propagation methods with appropriate scientific inputs for more economical and time efficient techniques for standard propagation protocols.