IPR 103 – Rustic dwarf arabic coffee cultivar more adapted to hot regions and poor soils

‘IPR 103’ was derived from a cross between “Catuaí” and “Icatu”. ‘IPR 103’ is a medium size dwarf cultivar with high rusticity, partially resistant to coffee leaf rust with late ripening. This cultivar is more adapted to hot regions and poor soils. It presents partial resistance to necrosis and mummification of young fruits on field conditions.


INTRODUCTION
The majority of arabic coffee areas in Brazil use cultivars of Catuaí germplasm.These cultivars present high productivity, wide adaptability and late ripening, similar to 'IPR 103', but it are susceptible to coffee leaf rust and young fruit necrosis and mummification.
'IPR 103' was derived from a cross between "Catuaí" and "Icatu" and has incorporated some traits by introgressed genes of C. canephora from "Icatu", such as biotic and abiotic rusticity.'IPR 103' is a medium size dwarf cultivar with partial resistance to leaf rust (Hemileia vastatrix Berk.et Br.) (Sera et al. 2010), partially resistant to necrosis and mummification of young fruits on field conditions (Sera et al. 2005, Sera et al. 2007) and late ripening.This cultivar is recommended for semi dense and dense planting systems in lower and higher temperature areas with annual average between 19 and 23 ºC, in the State of Paraná.

PEDIGREE AND IMPROVEMENT METHOD
'IPR 103' was developed using the genealogical method.It was derived from a cross between plants of "Catuaí" and "Icatu", performed at Instituto Agronômico de Campinas (IAC) in 1972.In 1977, IAPAR introduced the F 3 generation (IAC H 9878 -EP 187 c.582), named PR 77054.The F 4 progeny PR 77054-40 was selected.The plant number 10 was selected and it originated the F 5 progeny PR LF 77054-40-10, later named 'IPR 103' and released in 2006.

PERFORMANCE
'IPR 103' can be cultivated in regions with annual average temperature between 19 and 21 ºC, such as Londrina (580 m altitude) and Congonhinhas (750 m altitude) municipalities and in regions with annual average temperature between 22 and 23 ºC, such as Itaguajé (350 m altitude) and Lupionópolis municipalities.The 'IPR 103' was evaluated in three locations of Paraná State with 16 annual harvests and it was more productive than 'IAPAR 59' and 'Catuaí Vermelho IAC 81' (Table 1) because of rusticity and better performance to several biotic and abiotic stresses.
'IPR 103' is a medium size dwarf cultivar, similar to "Catuaí", recommended for spacing between plants varying from 0.50 to 0.80 m, depending on the annual average temperature of local cultivation and on the technologies used, such as fertilization, irrigation and pruning.In hot regions without irrigation, the spacing ought to be narrower since T Sera et al.
the canopy diameter and branching are usually smaller.On farms with fertirrigation, the spacing between rows and between plants can be larger.On farms where pruning are frequently used, the spacing can be smaller.Using wider spacing between plants will increase plant yield; hence, it will be necessary more nutrition.The spacing between rows can vary from 2.50 to 3.00 m, according to the coffee crop area and the level of mechanization.

OTHER TRAITS
'IPR 103' presents late ripening, even later than "Catuaí".At lower temperatures with annual average between 19 and 21 ºC, the ripening usually occurs around August.At higher temperatures with annual average between 22 and 23 ºC, the ripening usually occurs around June.
'IPR 103' can be used in association with other dwarf coffee cultivars with different ripening times (e.g.'IAPAR 59' = semi early, 'IPR 98' = medium, 'IPR 99' = semi late) in order to reduce the labor, infrastructure and equipment requirements.By using 'IPR 103' with other maturation cultivars group for harvest in different times, the rain risk at harvest is reduced and it is easier and cheaper to produce more quality coffee in the rainy and cool coffee regions of Paraná State.
'IPR 103' shows rusticity and better adaptation to high temperatures and poor soils, comparing to other compact cultivars such as "Catuaí" and 'IAPAR 59'.'IPR 103' was selected in coffee regions with poor and sandy soils, low altitudes and higher temperatures, with annual average between 21 and 23 ºC, in the State of Paraná.In this State, this cultivar is highly recommended for cultivation in the west and northwestern regions (Arenito Caiuá), and in lower altitudes of argillaceous soils regions.'IPR 103'could be planted in lower temperature areas with annual average between 19 and 20 ºC in Paraná, but it must be planted in areas with reduced frost risk since this cultivar presents late ripening.
Currently, 'IPR 103' is partially resistant (moderately susceptible) to rust physiological races present in Paraná State (Sera et al. 2010) and it may require chemical control, but with a lower number of fungicide applications in comparison with susceptible and highly susceptible cultivars.
'IPR 103' presents a good level of partial resistance (moderate resistance) to the symptoms of necrosis and mummification of fruits (Sera et al. 2005, Sera et al. 2007).These symptoms are being associated with the attack of Colletotrichum spp. or Colletotrichum gloeosporioides Penz (Juliatti andSilva 2001, Paradela-Filho et al. 2001).
The cup quality is similar or superior to "Catuaí".These traits and others are described in Table 2.

Table 1 .
Crop Breeding and Applied Biotechnology 13: 95-98, 2013 Brazilian Society of Plant Breeding.Printed in Brazil Annual average yield per hectare (bags of 60 kg ha -1 ) of'IPR  103', in comparison with other cultivars (Paraná State, Brazil)

Table 2 .
Morphological, physiological and agronomic traits of 'IPR 103' with the respective descriptions.