Pineapple Yield Research Articles

Combination of organic fertilizer and slow-release fertilizer increases pineapple yields, agronomic efficiency and reduces greenhouse gas emissions under reduced fertilization conditions in tropical areas

To ensure pineapple productivity, large amounts of chemical fertilizer are used in the tropics of China. However, the high temperatures, rainfall and low fertilizer utilization efficiencies lead to fertilizer leaching loss and greenhouse gas emissions, which are very unfavourable to the sustainable production of pineapple. The purpose of this study was to determine whether reducing fertilizer applications could increase pineapple yield, quality and agronomic efficiency and reduce the global warming potential. A 4-year field experiment with five fertilization pattern treatments (e.g., CK: no fertilization; NPK: traditional fertilization; INF: reduced nitrogen (N), phosphorus and potassium fertilizers; INF + M: based on INF, 20% N was replaced by organic fertilizer; INF + M + S: based on INF, 20% and 15% N were replaced by organic and slow-release fertilizers, respectively) was established to ascertain the potential role of reduced fertilization levels in increasing pineapple yield, quality and agronomic efficiency and reducing greenhouse gas emissions. The results revealed that compared with the NPK treatment, the INF, INF + M and INF + M + S treatments increased pineapple yields by 8.1%, 13.0% and 27.1% averaged over the two seasons, respectively, and significantly improved the agronomic efficiency and reduced the global warming potential and greenhouse gas emission intensity without compromising quality. In addition, when compared with INF treatment, the INF + M and INF + M + S treatments could significantly reduce the nitrous oxide and carbon dioxide emissions and thus decrease the global warming potential by 21.2% and 29.2%, respectively, and greenhouse gas emission intensity by 32.0% and 32.5%, respectively, averaged over two seasons. However, the INF + M and INF + M + S treatments showed no significant differences. The INF + M + S treatment provided the highest yields, agronomic efficiency and soil methane uptakes among all treatments (p < 0.05). The nitrous oxide and methane emissions showed significant positive correlations with soil moistures and temperatures, respectively. Meanwhile, both nitrous oxide and carbon dioxide showed significant positive correlations with the soil ammonium and nitrate contents. We highly recommend the INF + M + S treatment as an environmentally friendly fertilization strategy for pineapple in tropical regions with high yields, high efficiencies, and low greenhouse gas emissions.

Yield and quality of pineapple fertigated with treated wastewater

Yield and quality of pineapple fertigated with treated wastewater

Soil fertility, system productivity and economic viability of coconut based high density multi species cropping system in Tamil Nadu, India

Monocropping of coconut is no longer viable in the context of price aberrations of copra, debilitating pests and dreadful diseases and intercropping turned out to be an inevitable venture. A research experiment was pursued at the AICRP (Palms) centre, Coconut Research Station, Aliyarnagar, Tamil Nadu, India during 2013-18 to assess the impact of coconut based High Density Multi Species Cropping System (HDMSCS) with cocoa (CCRP accessions), banana (var. Nendran) and pineapple (var. Kew), on soil fertility, system productivity and economic viability. The experiment was conducted in a sandy clay loam soil taxonomically classified as Typic Haplustepts. Four treatments viz., T1: 75 per cent recommended dose of nutrients (RDN) as chemical fertilizers 25 per cent RDN through organic recycling with vermicompost, vermiwash application, biofertilizer application and green manuring with gliricidia loppings; T2: 50 per cent RDN as chemical fertilizers with 50 per cent RDN through organic sources, T3: 100 per cent RDN through organic sources and T4: sole chemical fertilization were imposed in blocks comprising of 25 coconut palms per block. Results revealed that integration of 75 per cent recommended dose of nutrients (RDN) through chemical fertilizers and 25 per cent through organic sources (T1) resulted in increased nut yield of coconut, dry bean yield of cocoa and fruit yield of banana and pineapple. Nut yield was conspicuously lower in monocropping compared to HDMSCS. Soil organic carbon (SOC), earthworm count and microbial population were higher in the treatment, which received 100 per cent RDN through organic sources (T3). Net Returns, B: C ratio and employment generation potential were higher in HDMSCS than coconut monoculture. Partitioning of the recommended dose of nutrients through 75 per cent chemical fertilizers and 25 per cent organic manures for coconut based high density multi species cropping integrated with cocoa, banana and pineapple paved the way for enhanced soil fertility, system productivity, profitability and sustainability of coconut system in Western Zone of Tamil Nadu, India.

A review of common diseases of pineapple: the causal pathogens, disease symptoms, and available control measures

Pineapple is a perennial fruit-bearing tropical plant that belongs to the Bromeliaceae family, which has more than 2500 species. Pineapple is known excellent source of minerals and vitamins. It produces substantial calcium, potassium, glucose, the proteindigesting enzyme bromelain, fibre, vitamin A, B and C. In Malaysia, twelve registered varieties of pineapple have been introduced and commercially planted such as Moris (AC1), Sarawak (AC2), Gandul (AC3), Maspine (AC4), Josapine (AC5) Yankee (AC6) Moris Gajah (AC7), N36 (AC8), MD2 (AC9), View of Sunset (AC10), Madu Kaca (AC11), and Keningau Diamond (AC12). The disease is one of the important factors that can contribute to the huge losses of pineapple yield worldwide. This review paper aimed to discuss the main diseases of pineapple and their control management, particularly in Malaysia. The common diseases of pineapple that cause significant yield losses in the farms such as mealybug wilt-associated virus, bacterial heart rot, fruit collapse, butt rot, fruitlet core rot, black rot, yeasty and fusariosis are highlighted and discussed in detail on the causal pathogens, disease symptoms and signs, disease infection and development. The available control measures for managing pineapple diseases were also included in this paper.

Mycorrhizal Inoculation and Chemical Fertilizer Interactions in Pineapple under Field Conditions

Excessive inorganic fertilizers applied to pineapple crops in Mexico cause the progressive degradation and pollution of soils in the short- and long-term, and they also increase production costs. An alternative to reduce excessive fertilization is its partial substitution by nutrition and growth enhancing arbuscular mycorrhizal fungi (AMF). The goal of this research was to compare the effect of AMF inoculation combined with different fertilizer doses and full chemical fertilization on pineapple yield variables in a commercial plantation. We used a randomized block design with six treatments: a non-inoculated control with 100% chemical fertilization, and five treatments with AMF inoculation and fertilization doses of 0%, 25%, 50%, 75%, and 100% chemical fertilization. There were four replicates of each treatment containing 30 plants in each experimental unit (plot). We measured the dry weight of the D-leaf 9 months after planting, and the root mycorrhizal colonization percentage, yield, and fruit quality after 18 months. Mycorrhizal inoculation equated to 100% chemical fertilization already when combined with 25% fertilization and surpassed it when combined with 50% fertilization in most of the yield variables measured. The fruit mass and organoleptic variables were significantly higher in mycorrhizal plants with 50% fertilization than in the non-inoculated control and the treatments inoculated with AMF and combined with 0%, 25%, 75%, and 100% of a dose of chemical fertilizer. Inoculation with mycorrhizal fungi in the field could reduce chemical fertilizer application by 50%, with no yield loss and with improved fruit quality.

Foliar Urea with N-(n-butyl) Thiophosphoric Triamide for Sustainable Yield and Quality of Pineapple in a Controlled Environment

In agricultural production, nitrogen loss leads to economic loss and is a high environmental risk affecting plant growth, yield, and quality. Use of the N fertilizer with a urease inhibitor is thus necessary to minimize N losses and increase the efficiency of N. This study aimed to evaluate the effects of N-(n-butyl) Thiophosphoric Triamide (NBPT) on the growth, yield, and quality of pineapple. The experiment involved two foliar fertilizer treatments: 1% (w/v) urea solution with NBPT (2.25 mL kg−1 urea) was treated as NLU (NBPT Liquid Urea), and the same concentration of urea without NBPT served as the control. Both were applied 12 times, starting 1 month after planting (MAP) and continuing once a month for 12 months. The application of urea with NBPT notably increased the above-ground dry biomass per plant (20% and 10% at 8 and 12 MAP, respectively), leaf area per plant (23% and 15% at 8 and 12 MAP, respectively), N accumulation per plant (10%), PFPN (Partial Factor Productivity) (13%), and average fruit weight (15%) compared to the treatment with urea alone (control). The analysis of quality parameters indicated that urea with NBPT improves TSS (Total Soluble Solids) (19%), ascorbic acid (10%), and sucrose (14%) but reduces the total organic acid content (21%) in pineapple. When using urea with a urease inhibitor (NBPT), there was a significant improvement in growth, yield, quality, and nitrogen use efficiency, with the additional benefit of reduced nitrogen losses, in combination with easy handling. Hence, urea with a urease inhibitor can be used as a viable alternative for increasing pineapple yield by boosting growth with better fruit quality.

Effect of Planting Density and K2O:N Ratio on the Yield, External Quality, and Traders' Perceived Shelf Life of Pineapple Fruits in Benin.

Quality, shelf life, and yield of a pineapple fruit are the important attributes for the producers and customers in the pineapple value chain of Benin, whereas poor quality, short shelf life, and low yield are the main constraints. We quantified the effects of planting density and K2O:N fertilizer ratio on the pineapple yield, external quality, and perceived shelf life in four on-farm experiments with cv. Sugarloaf in Benin; two experiments were installed in the long rainy season and two in the short rainy season. A split-plot design was used with the planting density as the main factor at three levels: 54,000, 66,600, and 74,000 plants.ha−1. The K2O:N ratio was a subfactor with three levels: K2O:N = 0.35 (farmers' practice), K2O:N = 1, and K2O:N = 2. The results showed that both factors had no effect on the crop development variables (such as the number of functional leaves and D-leaf length) at the moment of flowering induction. The planting density had no effect on the total weight per fruit, infructescence weight, total fruit length, infructescence length, crown length, or the fruit shelf life as perceived by traders. The yield increased from 54.9–69.1 up to 90.1 t.ha−1 with an increase in the planting density. The yield increase was not at the expense of the fruit weight. Increased K2O:N ratio led to a higher fruit weight whereas the fruit length was not affected. The shelf life of fruits produced at a K2O:N ratio of 1 and as perceived by traders was 6 days longer than that of fruits produced at a ratio of 0.35 (farmers' practice). Based on these results, we suggest the fresh pineapple farmers in Benin to use a combination of 66,600 plants.ha−1 with a K-fertilization scheme based on a K2O:N ratio of 1 to meet the expectation of both producers and customers in terms of fruit yield and fruit quality.

Pineapple yield and fruit quality in response to potassium fertilization

The pineapple (Ananas comosus L.), originally from South America, is the third most produced fruit in Brazil. The potassium nutrient plays a fundamental role on the fruit quality. The objective of this study was to evaluate the influence of potassium doses applied to the soil on fruit yield and on the physical and chemical characteristics of the Pérola pineapple cultivar. The design used randomized block design with four repetitions; the treatments consisted of five doses of K2O: 0; 222; 444; 666 and 888 kg ha−1 applied in the form of potassium chloride, divided into two applications, after floral induction. The evaluated variables were: fruit yield per hectare and pulp, fruit and crown fresh mass, fruit diameter, fruit and crown lengths, titratable acidity, soluble solids, vitamin C, juice pH and soluble solids/titratable acidity ratio. Potassic fertilization increased the yield of both fruit and pulp per hectare, the fruit and crown fresh mass, the diameter of the fruit, the lengths of the fruit and crown, titratable acidity, soluble solids, vitamin C and decreased the ratio of soluble solids to titratable acidity in the juice. The rise in potassium nutrition improves the quality and yield aspects of the pineapple ‘Pérola’ fruit.

Influence of Watering Solution and Phenotype on the Growth of &amp;lt;i&amp;gt;in Vitro&amp;lt;/i&amp;gt; Propagated Pineapple (Smooth Cayenne Cultivar) Plantlets during Acclimatization

Pineapple is the first fruit crop cultivated in south Benin that greatly contributes for food and nutritional security and farmers’ income. But the lack of homogenous planting material constitutes the major constraint for improving pineapple yield. In vitro micropropagation is now used in the production of homogenous and free disease planting materials of pineapple. However, the acclimatization to natural condition of pineapple plantlets is an important step in planting material production of this crop. Here, we determined the intrinsic and extrinsic factors which influence the behavior of plantlets during the acclimatization process. For this purpose, plantlets from different categories were selected, trimmed and planted on a horticultural substrate made up of potting soil, white sawdust and compost previously sterilized. The plantlets were then incubated in under acclimatization greenhouse with average temperature of 29˚C and 70.2% of humidity. A batch of plantlets was subjected to two different watering solutions: Shive and Robbins solution and NPK 14-6-5 foliar fertilizer. The results obtained initially showed high rate (100%) of survival and growth of the plantlets watered with Shive and Robbins solution against 50% of the plantlets watered with the foliar fertilizer solution. In addition, the plantlets with spread pores exhibiting the characteristics of which the number of leaves varies between 9 and 11, the weight between 1.2 and 1.5 g, the size of 4.5 to 5.5 cm, and a good junction between the aerial part and the root system were those which were successfully grown in acclimatization phase under greenhouse, unlike plantlets with erected pores having lower success rate. This study goes a long way in providing good procedures of acclimatization of homogenous and free disease planting material of pineapple to the famers.

EFFECTS OF COMPOST ON SOIL PROPERTIES AND YIELD OF PINEAPPLE (Ananas comusus L. MERR.) ON RED ACID SOIL, LAMPUNG, INDONESIA

Compost is an organic matter commonly used to improve the chemical and physical properties of soil, especially of marginal soil, where the limiting factors of the soil fertility are the lack of organic matter and low soil pH. One aim of this study is to determine the effect of compost application on the improvement of the chemical and physical properties of acid soils planted with pineapple. Another aim of this study is to determine the effect of compost in reducing the foliar fertilizer and the influence of this reduction on the pineapple yield. A factorial experiment was arranged in a randomized block design with two factors and three replications. The first factor was the rate of compost application with the following treatments: K0: no compost, K25: compost 25 t ha-1 and K50: compost 50 t ha-1, while the second factor was the reduction of foliar chemical fertilizer with the following treatments: P100: 100% of the standard fertilizer, P80: 80% of the standard fertilizer and P60: 60% of the standard fertilizer. The total combined treatments, i.e., nine treatments, consisted of K0P100, K0P80, K0P60, K25P100, K25P80, K25P60, K50P100, K50P80 and K50P60 with three replications. The results showed that the compost could improve the chemical and physical properties of acid soils, and the application of the compost dose of 25 t ha-1 enabled a reduction of foliar chemical fertilizer by 40% with no loss in yield. Keywords: Compost, Foliar spray, Pineapple, Reduction of foliar fertilizers, Red soil

Influence of shade intensity on growth, biomass allocation, yield and quality of pineapple in mango-based intercropping system

Fruit tree-based intercropping system is commonly practiced in India; however, optimization of light environment for intercrops is essentially required to enhance their productivity. Influence of three shade intensities were examined on growth, biomass allocation pattern, leaf chlorophyll content, nutrient uptake, fruit yield and quality of pineapple in mango-based intercropping system. Compared to the monoculture pineapple system (LE0), the mean shade intensity under LE1, LE2 and LE3 were 23.8 %, 48.6 % and 73.3 %, respectively, whereas the mean PAR availability was 76.2 %, 51.4 % and 26.7 %, respectively. Significantly higher absolute growth rate (AGR), crop growth rate (CGR) and relative growth rate (RGR) was recorded under medium shade intensity (LE2). Dry matter accumulation was significantly high under LE2 followed by LE3. The biomass accumulation was significantly high in leaf followed by fruit and stem, whereas root system exhibited minimum biomass accumulation. Biomass of leaf and crown decreased with the plant biomass, whereas the biomass of fruit, stem and sucker increased. Contents of Chl a, Chl b and Chl a + b increased with the shade intensity and were found maximum under LE3. A gradual increase in N and P contents were observed in the leaves of pineapple with the reduction in PAR transmittance. However, the K content was relatively high under LE2. Increased fruit yield, fruit weight and fruit/crown ratio were recorded under moderate shade intensity (LE2). Total soluble solids and sugar content marginally decreased with the reduction in light intensity, whereas titratable acidity increased. Sunburn intensity significantly reduced under LE2 and LE3. Path analysis studies indicated that plant biomass was that most important predictor for fruit yield in pineapple. Our findings demonstrate that in eastern tropical region of India pineapple may be cultivated as an intercrop with ∼50 % shade intensity since the performance of crop is significantly affected under monoculture system.

Effect of Application of POME and Recommended Fertilizer on Immature Oil Palm Intercropping with Pineapple, Low Country Wet Zone (WL2a) in Sri Lanka

Oil palm plantations in Sri Lanka have spread over 10,000 hectares’ in the wet zone of the Island In immature plantations, land productivity can be increased with some selected intercrops. Pineapple is one of the high demanded fruit crop and is a suitable candidate for intercrop. Palm oil mill effluent (POME) is a problematic waste to manage by mill operators which is generated during processing of fresh fruit bunch (FFB). The objectives of the study were to evaluate the efficiency of POME, effective land utilization, ground cover efficiency of intercrop and improvement of soil physicochemical properties. A field trial conducted at Thalgaswela estate (WL2a) in Galle district, Sri Lanka from 2019 June to 2020 June. Experiment was designed with Randomized Complete Block Design (RCBD) with seven treatments and three replicates. Fertilizers were applied to the pineapple plots according to the department of Agriculture (DOA) recommendations. Growth parameters were taken at monthly intervals and chlorophyll content were measured. Soil physical parameters were measured at the beginning and at the end of the experiment. Results were statistically analyzed with Minitab software. According to the experimental data, oil palm with cover crop and pineapple along with recommended fertilizer were shown effective land utilization, higher number of leaves per plant, highest leaf length, highest spade meter chlorophyll content, soil has highest moisture content. Treatment seven (T7) shows significantly higher number of fruit forming during the research period. To come to a firm recommendation on POME as an organic amendment and performance of pineapple yield, research should be continued for at least more than two yield cycles.

Genome-wide identification and expression analysis of the ERF transcription factor family in pineapple (Ananas comosus (L.) Merr.).

Pineapple (Ananas comosus (L.) Merr.) is an important tropical fruit with high economic value. The quality and yield of pineapple will be affected by various environmental conditions. Under adverse conditions, plants can produce a complex reaction mechanism to enhance their resistance. It has been reported that the member of ethylene responsive transcription factors (ERFs) plays a crucial role in plant developmental process and stress response. However, the function of these proteins in pineapple remains limited. In this study, a total of 74 ERF genes (AcoERFs) were identified in pineapple genome, named from AcoERF1 to AcoERF74, and divided into 13 groups based on phylogenetic analysis. We also analyzed gene structure, conserved motif and chromosomal location of AcoERFs, and the AcoERFs within the same group possess similar gene structures and motif compositions. Three genes (AcoERF71, AcoERF73 and AcoERF74) were present on unanchored scaffolds, so they could not be conclusively mapped on chromosome. Synteny and cis-elements analysis of ERF genes provided deep insight into the evolution and function of pineapple ERF genes. Furthermore, we analyzed the expression profiling of AcoERF in different tissues and developmental stages, and 22 AcoERF genes were expressed in all examined tissues, in which five genes (AcoERF13, AcoERF16, AcoERF31, AcoERF42, and AcoERF65) had high expression levels. Additionally, nine AcoERF genes were selected for functional verification by qRT-PCR. These results provide useful information for further investigating the evolution and functions of ERF family in pineapple.

Effects of time and height of shading on yield and quality of pineapple

Effects of time and height of shading on the sunburn rate, yield and quality of pineapples were investigated in order to provide a theoretical basis for high-quality pineapple production. Golden pineapple was used as the material, and three shading times (30 d, 45 d, and 60 d after flower-fading), and the heights of 0 cm, 20 cm, and 40 cm (the distance from the top of the plant) were set. Golden pineapple’s internal and external fruit qualities were measured. The results showed that the incidence of sunburn of pineapple fruits increased with the delay of the shading time, and no differences were found among three heights at 30 d after flower fading. When pineapple plants were shaded at 30 d after flower fading and at height of 0 cm, pineapple fruits showed good external qualities, including larger fruit size, less fruit eyes, less fruit shape index, larger fruit hardness, higher edible rate and good internal qualities, including higher soluble solid content, higher soluble sugar content and lower total acidity. Shading at 30 d after flower fading and at height of 0 cm was suggested in pineapple production.

Optimization of the flowering stage by using stimulants of calcium carbide and paclobutrazol on pineapple at post tin mining area

Bangka Island is the potential to increase pineapple production because of the availability of marginal land caused by tropical tin mining. The success of pineapple cultivation is determined by the formation of flowers that will become fruit. The flowering process can be accelerated using carbide and paclobutrazol. This research aimed to study the effect of Calcium carbide and paclobutrazol application as a flowering stimulant for flowering initiation and yield of pineapple in the post tin mining area. This research was conducted from January 2018 – July 2019 located in post tin mining area owned by PT Timah Tbk, Dwi Makmur Village, Merawang Subdistrict, Bangka Island using an experimental method with randomized block design with a single factor which was a type of flowering stimulant consist of calcium carbide [Calcium carbide] [P0] and paclobutrazol [P1]. The result showed that both of flowering stimulant gave significant effect to flowering time, fruit diameter, fruit length, fruit weight with crown, and fruit weight without the crown of pineapple. The fastest flowering duration showed in the pineapple with Carbide application in the post tin mining area.

Alternativas para o controle de plantas espontâneas no cultivo do abacaxizeiro

O objetivo do estudo foi verificar a viabilidade de utilizar restos culturais como cobertura de solo, além de métodos tradicionais, como forma de controlar as plantas espontâneas no cultivo do abacaxizeiro. O delineamento experimental empregado foi em blocos ao acaso, com três repetições, sendo utilizados oito tratamentos nas entrelinhas do abacaxizeiro: (1) herbicida; (2) roçada; (3) capina manual; cobertura do solo com (4) folhas e talos de caeté; (5) restos culturais de milho; (6) restos culturais de feijão; (7) folhas de cana-de-açúcar e (8) folhas de bananeira. Cada parcela foi constituída por quatro fileiras de abacaxizeiro em espaçamento de 1,0 x 0,2 m; cada fileira foi composta por 12 plantas, totalizando 48 por parcela. Avaliaram-se características morfométricas e qualitativas dos frutos de abacaxi, além da produção de plantas espontâneas. Os resultados indicaram que as maiores produções de massa seca das plantas espontâneas ocorreram nos tratamentos com herbicida e roçada em contaste com a produzida pelo feijão. A cobertura de solo com folhas de bananeira foi a mais promissora, pois foi similar aos tratamentos tradicionais capina e herbicida quanto à produtividade de abacaxi, dimensões dos frutos, massa de frutos sem coroa e qualidade de frutos, bem como controle de plantas espontâneas.

Implications of continuous and rotational cropping practices on soil bacterial communities in pineapple cultivation

Bacterial communities in cultivated soils contribute to soil organic matter dynamics and nutrient cycling. Despite numerous reports on the influence of cropping practices on soil microbial community structure, the knowledge of bacterial response to pineapple (Ananas comosus (L.) Merr) cropping systems is very limited. Here, rhizosphere and inter-row soil bacterial community composition in continuous and rotational pineapple (variety: Comte de Paris) cropping at two sites (Leizhou and Xuwen in Guangdong Province, China) during summer (May 2017) and winter (December 2017) were assessed via Illumina high-throughput sequencing of PCR-amplified 16S rRNA genes. Our results showed that: (1) leaf nitrogen, chlorophyll contents and yield of pineapple under rotational cropping were significantly higher than continuous cropping; (2) significant differences of soil bacterial community composition were observed between continuous cropping and rotational cropping; (3) Ten representative differentially distributed genera: Acidobacteria_unclassified, Castellaniella, Holophagae_unclassified, Frigoribacterium, Crenotalea, Nitrosospira, Clostridium_sensu_stricto_8, Pusillimonas, Acidiphilium and Mizugakiibacter were identified, and divided into three functional types: acidophilic, denitrifying bacteria, and ammonia-oxidizing bacteria; and (4) the relative abundances of these 10 differentially distributed genera were significantly or highly significantly correlated with leaf nitrogen, chlorophyll contents and yield of pineapple. Due to these results, we deduce that rotational cropping practice may increases pineapple yield by affecting bacterial community structure.

APPLICATION OF GA3 AND HARVEST SEASON INTERFERE IN PINEAPPLE YIELD AND FRUIT QUALITY

This study aimed to evaluate the effect of GA3 (gibberellic acid) application on growing pineapple ‘Perola’ fruits, and also the harvest season on yield, and fruit quality. The experimental design used was randomized blocks in 5×2 factorial design, being the first factor the application of GA3, and the second the harvest season, totaling in 10 treatments with four replicates, in split-plot plots. The treatments tested were: 1) GA3 application after the appearance of the first flower open on the inflorescence; 2) application of GA3 after the closing of the flowers in the inflorescence; 3) application of GA3 45 days before the first harvest; 4) two applications of GA3: one after the closing of flowers and another 45 days before the first fruits harvest; and 5) without application of GA3. Two harvest seasons were evaluated: 150 and 180 days after the floral induction. The phytoregulator Pro-Gibb® in a concentration of 200 mg L-1 of GA3 was adopted. The variables assessments were: fruit length with crown and without, crown length and mass, crownless fruit mass, average fruit mass and yield, titratable acidity, total soluble solids, and pH of the juice. The harvest of pineapple fruits held 180 days after floral induction, combined with an application of GA3 45 days before the harvest, provided greater yield while maintaining and improving the quality of pineapple ‘Perola’ fruits. The use of GA3 did not influence the pineapple yield when the harvest is performed early, i.e. 150 days after flower induction.

Quantification of yield loss to pineapple heart rot disease on pineapple cultivars in Uganda

1 ABSTRACT Pineapple (Ananas comosus L. Merr) is an important fruit crop in Uganda. Pineapple production in Uganda is devastated by pineapple heart rot disease (PHRD) which is associated with serious economic and yield losses. Therefore, this study quantified yield loss on five pineapple cultivars to pineapple heart rot disease in central Uganda. Five cultivars (Smooth Cayenne, Victoria, Sasilimu, MD-2 hybrid and Red Spanish) were tested for latent infection by planting the suckers in buckets containing 10 kilograms of sterile soil for four month. Disease free suckers, four month old, of average size from the five cultivars were planted in pots containing 10 kilograms of sterile clay-loam soil in the screen house in 2016/2017 in a completely randomized design (CRD). Treatments consisted of protected pots, un-protected pots and control pots respectively. Pineapple plants in the protected pots had their suckers dipped for three minutes in a solution of Metalaxyl (Active Ingredients: methoxyacetyl)-N-(2, 6-xylyl)-DL-alaninate 8%) before planting and later sprayed with a solution of Fosetyl Al (Active Ingredients: Aluminum tris 80%) using a backpack sprayer with Hardir flat spray nozzles three weeks after planting. Pineapple plants in the unprotected pots were not treated with any fungicide. The suckers in protected and unprotected pots were inoculated with 108ml of zoospores using needle-mediated leaf base wound technique. Control pots were not inoculated. Data on pineapple heart rots caused by the pathogen was collected from all the pots and thus used to compute yield loss per cultivar. Data was analyzed usin analysis of variance (ANOVA) of the GenStat computer program (15th edition). Pineapple heart rot disease (PHRD) significantly (P&lt;0.001) reduced pineapple yield in the un-protected pots across all the five cultivars evaluated in both trial one and trial two. Metalaxyl (Ridomil) and Fosetyl Al treatment significantly (P&lt;0.001) reduced yield losses in all the five cultivars used in the Protected pots in trial one and trial two respectively. The highest and lowest yield loss was recorded in cultivar Victoria and Smooth Cayenne respectively. PHRD can cause 100% yield loss. Metalaxyl (Ridomill) and Fosetyl Al is recommended for the control of PHRD in Uganda

Fitting Pineapple (Ananas comosus L.) with Rainfed Rice in the Cropping Sequence in Eastern India

In eastern India, the majority of areas under rainfed ecosystem are left fallow after kharif rice mainly due to lack of availability of irrigation water. Under this situation, pineapple is a suitable crop due to its adaptation system of crassulacean acid metabolism for photosynthetic carbon fixation. Pineapple is a long-duration crop (16–18 months) with irregular flowering behaviour. Hence, the present study was undertaken to study the feasibility of growing pineapple crop after harvest of kharif rice in a yearly sequence at the Research Farm of ICAR-Indian Institute of Water Management, Mendhasal, Khurda (Odisha), for two consecutive years (2009–2010 and 2010–2011). Ethephon hormone was applied at 10-month stage of crop to induce uniform and early flowering. In addition to this general treatment, spray of planofix at 50 mg l−1 (after 15 days of ethephon application at 20 mg l−1) resulted in the maximum flowering (81.2%). Similarly, 79.9% flowering was recorded when the plants were grown under shade. Also, spray of planofix resulted in the highest fruit yield (16.9 t ha−1) of pineapple due to increased fruit size. Fruit quality in terms of total soluble solids (14.85%) and vitamin C (150.18 mg kg−1) content was improved, and fruit acidity (0.58%) was decreased with spray of planofix. Therefore, pineapple can be grown in rice-based cropping system after harvest of kharif rice with suitable hormonal treatment, which will bring down the duration of pineapple crop to about 14 months (8 months in nursery and 6 months in main field).